In a railcar bogie, an axle box accommodating a bearing rotatably supporting a wheelset is supported by a bogie frame through an axle box suspension (see PTL 1, for example).
For example, in the bogie of PTL 1, wheel load adjusting work of adjusting wheel load balance among wheels is performed by inserting a liner between an axle box and an axle spring or pulling out the inserted liner to change a spring constant.